Abstract:

International literature indicates that the rates of obesity are increasing in OECD countries and that there are significant health risks to individuals who are classified as obese. Research has also highlighted that obesity is likely to be more pronounced in people who have an intellectual disability (ID). Despite this association there has been little research into the reasons why this population is overrepresented in obesity statistics. Furthermore, except for the brief report derived from this thesis (Stedman & Leland, 2010), there are no published New Zealand data on the rates of obesity among people who have an intellectual disability.

In the present study I accessed a database containing anonymous data for a sample of New Zealanders who have an intellectual disability. Ninety-eight participants out of 141 in the database had complete and up to date data. The group with complete data did not significantly differ from the group with incomplete data in gender or hours of staff support. Participants’ body mass index (BMI) was used to estimate rates of obesity within the sample. Comparisons were made with the general rates of obesity in adults reported by the New Zealand Ministry of Health (2008) using each of the BMI categories; underweight (< 18.50), normal (18.50 – 24.99), overweight (25.00 – 29.99) and obese (≥ 30.00). Obesity was further broken down into classes one (30.00 – 34.99), two (35.00 – 39.99) and three (≥ 40.00).

There were significantly higher rates of people with a BMI ≥ 30.00, in the group who had an intellectual disability (50.98%; general population 26.50%). There were significantly more adults who had an intellectual disability in all three BMI classes, with the most significant difference in class three.

While there were more obese men and women who have an intellectual disability in this sample than would be expected, women were found in higher than expected rates in class two (BMI 35.00 – 39.99) and class three (BMI ≤ 40.00). Research into the causal factors and potential interventions specific to men and women in this population to promote and maintain weight loss are warranted.